cybermecium Posted October 30, 2006 Share Posted October 30, 2006 I was looking through a book on Weber carburetors that I have, and saw a picture with a description of an old Alfa Romeo engine, 1600cc inline 4 with twin turbochargers driven off of engine oil pressure. Has anybody heard of or seen this done on any other car? It seems like driving the turbo from oil pressure (especially with a large powerful oil pump specifically for the purpose of driving the turbo/s) would work pretty well because 1- turbo is obviously well lubricated, 2- turbo stays much cooler because its not being fed by hot exhaust gas. Can anybody point out some more advantages or disadvantages to a hydraulic turbocharger? I might see about getting one made, a total custom job of course. Jake Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted October 30, 2006 Share Posted October 30, 2006 I read a book on airplane engines that had a article about an italian ww2 aircfraft engine that was designed to work the same way. It never went into production though. I have been thinking about this for a good 10 years or so now. I was looking for a really flat torque curve where max boot was reached at very low rpm and then you would just bleed of the preessure to maintain that boost level as rpm increased. Havent done anything other then think about it. Douglas Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 30, 2006 Share Posted October 30, 2006 At that point it would be a supercharger and not a turbocharger. It is driven by engine torque, albeit via a hydraulic coupling. You are not going to run a blower off the little oil pump in a normal car motor. You will basically need to set up a dedicated pump and drive system. Most likely belt driven. At which point you might as well run the belt to the blower directly. The WWII German ME 109 had a variable speed supercharger that I believe was driven off some type of hydraulic pump. The advantage of this in an aircraft is you can vary the boost with the changing air densities with altitude. The British Spitfire had two speed superchargers that essentially switched gears (same as a differetn pulley size). The problem with that is the two different speeds were optimized to operate at different altitudes, so the engine performance degraded when operating at an altitude near the blower shift point. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted October 30, 2006 Share Posted October 30, 2006 Continuously variable pullies... worth considering for SC's? http://auto.howstuffworks.com/cvt.htm (middle of the page) Quote Link to comment Share on other sites More sharing options...
Tony D Posted October 31, 2006 Share Posted October 31, 2006 There is a variable drive assembly that uses a CVT and ball bearings to transmit the torque. Can't remember where I saw the writeup, it was in an English Magazine about a year ago, best I can do. Something about sepcial fluid couplings, and speed increasing sheaves with the ball bearings moving outward to slow the compressor at higher speeds, and they went towards the center speeding it up at lower speeds. It made the centrifugal supercharger that acted like more conventional superchargers, giving a more linear response in HP and flat torque, instead of the non-linear response typical to the centrifugal impeller wheel. BTW, "might as well use a belt" and poo-poohing hydrostatics may be a bit short sighted. True, you will have to use a dedicated pump, but the transmission of the power is seamless and easily accomplished around corners, and even transmitted elsewhere in the vehicle! Placing a hydrostatically driven roots with the rotor centerline perpindicular to the crankshaft, and standing it up at the rear of the engine bay is a packaging idea not seen with a conventional belt drive! Hydrostatic drive is far easier to accomplish at a 5hp level than even electricity in current automobiles. But with packaging similarities to the electrical option! Quote Link to comment Share on other sites More sharing options...
veritech-z Posted October 31, 2006 Share Posted October 31, 2006 I worked with an old timer who claimed he once had some kind of ford production with what he called "an oil driven supercharger" on it. He didn't know much about it, just said the car hauled ass for being such a sled. He was a kid at the time, it was a 50's car, but I don't remember the model. Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted October 31, 2006 Share Posted October 31, 2006 I would be more worried about the drive loss inherent in going though so many medium changes. Quote Link to comment Share on other sites More sharing options...
Cruez Posted October 31, 2006 Share Posted October 31, 2006 If you think about it, you should be able to get some pretty high pressures to feed it.. hmmmm.. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 31, 2006 Share Posted October 31, 2006 BTW, "might as well use a belt" and poo-poohing hydrostatics may be a bit short sighted. I wasn't poo-poohing the idea. That is an interesting point about changing the characteristics of the centrifugal supercharger. I wasn’t aware of that but it makes perfect sense. Likewise, I hadn’t thought about the mounting options of a fluid drive, but definitely a plus for situations with limited space. Getting back to the original post, maybe it is just me but I got the impression that the original poster was looking to drive the blower off the existing oil system. Simple ideas like that are usually the best. What will keep that idea from working is the amount of power consumed by blowers. I have read articles that claim the blower can consume 20% of the engine output. So a little 5 HP blower drive isn’t going to be good for much. Have also read that centrifugal superchargers spin at 50 to 60 thousand RPM. Trying to one-off a drive system like that seems like a real challenge. Similarly I doubt there are many off the shelf components that can be bolted together to build such a system. So since there are a lot of off the shelf, belt driven options out there, I still say you “might as well use a beltâ€. BTW, I did some internet searches and turns out the DB601 engine in the ME 109 did use a variable speed hydraulic drive to spin a centrifugal supercharger. Apparently it was the first of it’s kind and fully automated. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted October 31, 2006 Share Posted October 31, 2006 Kiss... Imo. Quote Link to comment Share on other sites More sharing options...
cybermecium Posted October 31, 2006 Author Share Posted October 31, 2006 I think going through the medium changes of mechanical belt connection to hydraulic fluid would be worth the fact that the supercharger would be driven, lubricated, and cooled by the same system. Also- if the oil supply cuts out, the supercharger stops, preventing it from running without cooling or lubrication. Jake Quote Link to comment Share on other sites More sharing options...
cybermecium Posted October 31, 2006 Author Share Posted October 31, 2006 Getting back to the original post, maybe it is just me but I got the impression that the original poster was looking to drive the blower off the existing oil system. I guess you didn't read the part I wrote about having a powerful dedicated oil pump specifically for driving the turbine.... Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 31, 2006 Share Posted October 31, 2006 I guess you didn't read the part I wrote about having a powerful dedicated oil pump specifically for driving the turbine.... Yeah, must have been me then. Not an uncommon occurance. BTW, you don't have the same heat issues with a supercharger that you do with a turbo. Are standard blowers even hooked up to the oil system or do they have roller bearings? Quote Link to comment Share on other sites More sharing options...
rztmartini Posted October 31, 2006 Share Posted October 31, 2006 couldnt you just convert to a dry sump system and run it off of that? seems to me like you would be killing two birds with one stone... Quote Link to comment Share on other sites More sharing options...
alexideways Posted November 18, 2006 Share Posted November 18, 2006 I read about that about 5 years ago in (don't laugh) sportcompactcar magazine, back when they were'nt owned by primedia. Dave Coleman wrote the article. It was Garrett who was working on the idea at the time and it looked verry promising. They were actually developping it for heavy equipement industry. After a while of not having any news on the subject I e-mailed Mr. Coleman myself to ask about it, his answer was that even though he was as enthusiastic as I was, he did'nt think we'd see that for cars in the near futur. Quote Link to comment Share on other sites More sharing options...
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